Q and A: Who is Ukraine's next president?

More than three months after Ukraine's president fled to Russia in the wake of months of street protests, Petro Poroshenko is to be inaugurated on Saturday as the troubled country's new leader. The billionaire, widely called "the Chocolate King" because his fortune is rooted in the candy business, faces huge challenges posed by the violent insurgency in Ukraine's east and the country's stumbling, corruption-plagued economy. A look at Poroshenko and what's ahead for him:

Who is the chocolate king?The 48-year-old, who is estimated by Forbes magazine to be worth $1.6 billion, started his rise by importing cocoa beans into the Soviet Union in 1991. The project ballooned into the immensely popular candy manufacturer Roshen, the foundation of a business empire that now includes ship-building and one of the country's most influential TV stations.

Unlike many other Ukrainian billionaires, Poroshenko did not make his money in murky post-Soviet privatizations, boosting his reputation as a "good tycoon."

What are his politics?Poroshenko began his political career in 1998 as a lawmaker in a Russia-friendly party and went on in 2001 to help found Party of Regions, the political engine behind ousted president Viktor Yanukovych. But in 2004 he threw his weight behind the Orange Revolution protests that arose after fraud-plagued presidential elections.

He served as head of national security for a few months, but stepped down after months of feuding with the prime minister and allegations of improperly trying to help one of Ukraine's major tycoons. He later returned to serve as foreign minister, and briefly as economics minister after Yanukovych came to power in 2010. He catapulted back into the public eye by allying himself early and openly with the anti-Yanukovych protest movement that broke out in late November 2013.

Supporters regard his moving between factions as a sign of pragmatism amid Ukraine's highly polarized politics. Poroshenko allied with a potential rival, former boxing champion Vitali Klitschko, endorsing him for Kiev mayor as Klitschko endorsed Poroshenko for president.

Poroshenko supports signing an association agreement with the European Union, but has spoken against holding a vote on whether Ukraine should seek NATO membership. He says it's important to mend ties with Russia quickly; relations with Moscow should be equal and should not undermine Ukrainians' desire for closer ties with the European Union, he says.

What will he do next?Poroshenko faces a growing pro-Russian uprising in the east of the country, where officials say more than 200 people have been killed in clashes between insurgents and Ukrainian forces. Many will expect Poroshenko to speedily bring the conflict under control. He could also defuse it through constitutional reforms that devolve more powers to regions and by giving up certain prerogatives, such as the ability to appoint governors.

Ukraine's cash-strapped government, desperate to receive the full $17 billion loan package promised by the International Monetary Fund, will have to undertake serious reforms early in Poroshenko's tenure as president.

Poroshenko also faces a major hurdle in encouraging lawmakers in parliament to agree to hold elections this year instead of in 2017 as scheduled. If he fails, he could face the same challenges as the Orange Revolution government, which took two years to hold parliamentary elections and soon became bogged down by infighting.